// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_
#define UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_

#include <stddef.h>
#include <windows.h>

#include <set>
#include <vector>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string16.h"
#include "base/win/scoped_gdi_object.h"
#include "base/win/win_util.h"
#include "ui/accessibility/ax_enums.h"
#include "ui/base/ui_base_types.h"
#include "ui/base/win/window_event_target.h"
#include "ui/events/event.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/sequential_id_generator.h"
#include "ui/gfx/win/window_impl.h"
#include "ui/views/views_export.h"

namespace gfx {
class Canvas;
class ImageSkia;
class Insets;
namespace win {
    class DirectManipulationHelper;
} // namespace win
} // namespace gfx

namespace ui {
class ViewProp;
}

namespace views {

class FullscreenHandler;
class HWNDMessageHandlerDelegate;
class WindowsSessionChangeObserver;

// These two messages aren't defined in winuser.h, but they are sent to windows
// with captions. They appear to paint the window caption and frame.
// Unfortunately if you override the standard non-client rendering as we do
// with CustomFrameWindow, sometimes Windows (not deterministically
// reproducibly but definitely frequently) will send these messages to the
// window and paint the standard caption/title over the top of the custom one.
// So we need to handle these messages in CustomFrameWindow to prevent this
// from happening.
const int WM_NCUAHDRAWCAPTION = 0xAE;
const int WM_NCUAHDRAWFRAME = 0xAF;

// IsMsgHandled() and BEGIN_SAFE_MSG_MAP_EX are a modified version of
// BEGIN_MSG_MAP_EX. The main difference is it uses a WeakPtrFactory member
// (|weak_factory|) that is used in _ProcessWindowMessage() and changing
// IsMsgHandled() from a member function to a define that checks if the weak
// factory is still valid in addition to the member. Together these allow for
// |this| to be deleted during dispatch.
#define IsMsgHandled() !ref.get() || msg_handled_

#define BEGIN_SAFE_MSG_MAP_EX(weak_factory)                                     \
private:                                                                        \
    BOOL msg_handled_;                                                          \
                                                                                \
public:                                                                         \
    /* "handled" management for cracked handlers */                             \
    void SetMsgHandled(BOOL handled)                                            \
    {                                                                           \
        msg_handled_ = handled;                                                 \
    }                                                                           \
    BOOL ProcessWindowMessage(HWND hwnd,                                        \
        UINT msg,                                                               \
        WPARAM w_param,                                                         \
        LPARAM l_param,                                                         \
        LRESULT& l_result,                                                      \
        DWORD msg_map_id = 0) override                                          \
    {                                                                           \
        base::WeakPtr<HWNDMessageHandler> ref(weak_factory.GetWeakPtr());       \
        BOOL old_msg_handled = msg_handled_;                                    \
        BOOL ret = _ProcessWindowMessage(hwnd, msg, w_param, l_param, l_result, \
            msg_map_id);                                                        \
        if (ref.get())                                                          \
            msg_handled_ = old_msg_handled;                                     \
        return ret;                                                             \
    }                                                                           \
    BOOL _ProcessWindowMessage(HWND hWnd,                                       \
        UINT uMsg,                                                              \
        WPARAM wParam,                                                          \
        LPARAM lParam,                                                          \
        LRESULT& lResult,                                                       \
        DWORD dwMsgMapID)                                                       \
    {                                                                           \
        base::WeakPtr<HWNDMessageHandler> ref(weak_factory.GetWeakPtr());       \
        BOOL bHandled = TRUE;                                                   \
        hWnd;                                                                   \
        uMsg;                                                                   \
        wParam;                                                                 \
        lParam;                                                                 \
        lResult;                                                                \
        bHandled;                                                               \
        switch (dwMsgMapID) {                                                   \
        case 0:

// An object that handles messages for a HWND that implements the views
// "Custom Frame" look. The purpose of this class is to isolate the windows-
// specific message handling from the code that wraps it. It is intended to be
// used by both a views::NativeWidget and an aura::WindowTreeHost
// implementation.
// TODO(beng): This object should eventually *become* the WindowImpl.
class VIEWS_EXPORT HWNDMessageHandler : public gfx::WindowImpl,
                                        public ui::WindowEventTarget {
public:
    explicit HWNDMessageHandler(HWNDMessageHandlerDelegate* delegate);
    ~HWNDMessageHandler() override;

    void Init(HWND parent, const gfx::Rect& bounds);
    void InitModalType(ui::ModalType modal_type);

    void Close();
    void CloseNow();

    gfx::Rect GetWindowBoundsInScreen() const;
    gfx::Rect GetClientAreaBoundsInScreen() const;
    gfx::Rect GetRestoredBounds() const;
    // This accounts for the case where the widget size is the client size.
    gfx::Rect GetClientAreaBounds() const;

    void GetWindowPlacement(gfx::Rect* bounds,
        ui::WindowShowState* show_state) const;

    // Sets the bounds of the HWND to |bounds_in_pixels|. If the HWND size is not
    // changed, |force_size_changed| determines if we should pretend it is.
    void SetBounds(const gfx::Rect& bounds_in_pixels, bool force_size_changed);

    void SetSize(const gfx::Size& size);
    void CenterWindow(const gfx::Size& size);

    void SetRegion(HRGN rgn);

    void StackAbove(HWND other_hwnd);
    void StackAtTop();

    void Show();
    void ShowWindowWithState(ui::WindowShowState show_state);
    void ShowMaximizedWithBounds(const gfx::Rect& bounds);
    void Hide();

    void Maximize();
    void Minimize();
    void Restore();

    void Activate();
    void Deactivate();

    void SetAlwaysOnTop(bool on_top);

    bool IsVisible() const;
    bool IsActive() const;
    bool IsMinimized() const;
    bool IsMaximized() const;
    bool IsAlwaysOnTop() const;

    bool RunMoveLoop(const gfx::Vector2d& drag_offset, bool hide_on_escape);
    void EndMoveLoop();

    // Tells the HWND its client area has changed.
    void SendFrameChanged();

    void FlashFrame(bool flash);

    void ClearNativeFocus();

    void SetCapture();
    void ReleaseCapture();
    bool HasCapture() const;

    FullscreenHandler* fullscreen_handler() { return fullscreen_handler_.get(); }

    void SetVisibilityChangedAnimationsEnabled(bool enabled);

    // Returns true if the title changed.
    bool SetTitle(const base::string16& title);

    void SetCursor(HCURSOR cursor);

    void FrameTypeChanged();

    void SetWindowIcons(const gfx::ImageSkia& window_icon,
        const gfx::ImageSkia& app_icon);

    void set_remove_standard_frame(bool remove_standard_frame)
    {
        remove_standard_frame_ = remove_standard_frame;
    }

    void set_use_system_default_icon(bool use_system_default_icon)
    {
        use_system_default_icon_ = use_system_default_icon;
    }

    void SetFullscreen(bool fullscreen);

    // Updates the window style to reflect whether it can be resized or maximized.
    void SizeConstraintsChanged();

private:
    typedef std::set<DWORD> TouchIDs;

    // Overridden from WindowImpl:
    HICON GetDefaultWindowIcon() const override;
    HICON GetSmallWindowIcon() const override;
    LRESULT OnWndProc(UINT message, WPARAM w_param, LPARAM l_param) override;

    // Overridden from WindowEventTarget
    LRESULT HandleMouseMessage(unsigned int message,
        WPARAM w_param,
        LPARAM l_param,
        bool* handled) override;
    LRESULT HandleKeyboardMessage(unsigned int message,
        WPARAM w_param,
        LPARAM l_param,
        bool* handled) override;
    LRESULT HandleTouchMessage(unsigned int message,
        WPARAM w_param,
        LPARAM l_param,
        bool* handled) override;

    LRESULT HandleScrollMessage(unsigned int message,
        WPARAM w_param,
        LPARAM l_param,
        bool* handled) override;

    LRESULT HandleNcHitTestMessage(unsigned int message,
        WPARAM w_param,
        LPARAM l_param,
        bool* handled) override;

    void HandleParentChanged() override;

    // Returns the auto-hide edges of the appbar. See
    // ViewsDelegate::GetAppbarAutohideEdges() for details. If the edges change,
    // OnAppbarAutohideEdgesChanged() is called.
    int GetAppbarAutohideEdges(HMONITOR monitor);

    // Callback if the autohide edges have changed. See
    // ViewsDelegate::GetAppbarAutohideEdges() for details.
    void OnAppbarAutohideEdgesChanged();

    // Can be called after the delegate has had the opportunity to set focus and
    // did not do so.
    void SetInitialFocus();

    // Called after the WM_ACTIVATE message has been processed by the default
    // windows procedure.
    void PostProcessActivateMessage(int activation_state, bool minimized);

    // Enables disabled owner windows that may have been disabled due to this
    // window's modality.
    void RestoreEnabledIfNecessary();

    // Executes the specified SC_command.
    void ExecuteSystemMenuCommand(int command);

    // Start tracking all mouse events so that this window gets sent mouse leave
    // messages too.
    void TrackMouseEvents(DWORD mouse_tracking_flags);

    // Responds to the client area changing size, either at window creation time
    // or subsequently.
    void ClientAreaSizeChanged();

    // Returns the insets of the client area relative to the non-client area of
    // the window.
    bool GetClientAreaInsets(gfx::Insets* insets) const;

    // Resets the window region for the current widget bounds if necessary.
    // If |force| is true, the window region is reset to NULL even for native
    // frame windows.
    void ResetWindowRegion(bool force, bool redraw);

    // Enables or disables rendering of the non-client (glass) area by DWM,
    // under Vista and above, depending on whether the caller has requested a
    // custom frame.
    void UpdateDwmNcRenderingPolicy();

    // Calls DefWindowProc, safely wrapping the call in a ScopedRedrawLock to
    // prevent frame flicker. DefWindowProc handling can otherwise render the
    // classic-look window title bar directly.
    LRESULT DefWindowProcWithRedrawLock(UINT message,
        WPARAM w_param,
        LPARAM l_param);

    // Lock or unlock the window from being able to redraw itself in response to
    // updates to its invalid region.
    class ScopedRedrawLock;
    void LockUpdates(bool force);
    void UnlockUpdates(bool force);

    // Stops ignoring SetWindowPos() requests (see below).
    void StopIgnoringPosChanges() { ignore_window_pos_changes_ = false; }

    // Attempts to force the window to be redrawn, ensuring that it gets
    // onscreen.
    void ForceRedrawWindow(int attempts);

    // Message Handlers ----------------------------------------------------------

    BEGIN_SAFE_MSG_MAP_EX(weak_factory_)
    // Range handlers must go first!
    CR_MESSAGE_RANGE_HANDLER_EX(WM_MOUSEFIRST, WM_MOUSELAST, OnMouseRange)
    CR_MESSAGE_RANGE_HANDLER_EX(WM_NCMOUSEMOVE,
        WM_NCXBUTTONDBLCLK,
        OnMouseRange)

    // CustomFrameWindow hacks
    CR_MESSAGE_HANDLER_EX(WM_NCUAHDRAWCAPTION, OnNCUAHDrawCaption)
    CR_MESSAGE_HANDLER_EX(WM_NCUAHDRAWFRAME, OnNCUAHDrawFrame)

    // Vista and newer
    CR_MESSAGE_HANDLER_EX(WM_DWMCOMPOSITIONCHANGED, OnDwmCompositionChanged)

    // Non-atlcrack.h handlers
    CR_MESSAGE_HANDLER_EX(WM_GETOBJECT, OnGetObject)

    // Mouse events.
    CR_MESSAGE_HANDLER_EX(WM_MOUSEACTIVATE, OnMouseActivate)
    CR_MESSAGE_HANDLER_EX(WM_MOUSELEAVE, OnMouseRange)
    CR_MESSAGE_HANDLER_EX(WM_NCMOUSELEAVE, OnMouseRange)
    CR_MESSAGE_HANDLER_EX(WM_SETCURSOR, OnSetCursor);

    // Key events.
    CR_MESSAGE_HANDLER_EX(WM_KEYDOWN, OnKeyEvent)
    CR_MESSAGE_HANDLER_EX(WM_KEYUP, OnKeyEvent)
    CR_MESSAGE_HANDLER_EX(WM_SYSKEYDOWN, OnKeyEvent)
    CR_MESSAGE_HANDLER_EX(WM_SYSKEYUP, OnKeyEvent)

    // IME Events.
    CR_MESSAGE_HANDLER_EX(WM_IME_SETCONTEXT, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_IME_STARTCOMPOSITION, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_IME_COMPOSITION, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_IME_ENDCOMPOSITION, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_IME_REQUEST, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_IME_NOTIFY, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_CHAR, OnImeMessages)
    CR_MESSAGE_HANDLER_EX(WM_SYSCHAR, OnImeMessages)

    // Scroll events
    CR_MESSAGE_HANDLER_EX(WM_VSCROLL, OnScrollMessage)
    CR_MESSAGE_HANDLER_EX(WM_HSCROLL, OnScrollMessage)

    // Touch Events.
    CR_MESSAGE_HANDLER_EX(WM_TOUCH, OnTouchEvent)

    // Uses the general handler macro since the specific handler macro
    // MSG_WM_NCACTIVATE would convert WPARAM type to BOOL type. The high
    // word of WPARAM could be set when the window is minimized or restored.
    CR_MESSAGE_HANDLER_EX(WM_NCACTIVATE, OnNCActivate)

    // This list is in _ALPHABETICAL_ order! OR I WILL HURT YOU.
    CR_MSG_WM_ACTIVATEAPP(OnActivateApp)
    CR_MSG_WM_APPCOMMAND(OnAppCommand)
    CR_MSG_WM_CANCELMODE(OnCancelMode)
    CR_MSG_WM_CAPTURECHANGED(OnCaptureChanged)
    CR_MSG_WM_CLOSE(OnClose)
    CR_MSG_WM_COMMAND(OnCommand)
    CR_MSG_WM_CREATE(OnCreate)
    CR_MSG_WM_DESTROY(OnDestroy)
    CR_MSG_WM_DISPLAYCHANGE(OnDisplayChange)
    CR_MSG_WM_ENTERMENULOOP(OnEnterMenuLoop)
    CR_MSG_WM_EXITMENULOOP(OnExitMenuLoop)
    CR_MSG_WM_ENTERSIZEMOVE(OnEnterSizeMove)
    CR_MSG_WM_ERASEBKGND(OnEraseBkgnd)
    CR_MSG_WM_EXITSIZEMOVE(OnExitSizeMove)
    CR_MSG_WM_GETMINMAXINFO(OnGetMinMaxInfo)
    CR_MSG_WM_INITMENU(OnInitMenu)
    CR_MSG_WM_INPUTLANGCHANGE(OnInputLangChange)
    CR_MSG_WM_KILLFOCUS(OnKillFocus)
    CR_MSG_WM_MOVE(OnMove)
    CR_MSG_WM_MOVING(OnMoving)
    CR_MSG_WM_NCCALCSIZE(OnNCCalcSize)
    CR_MSG_WM_NCHITTEST(OnNCHitTest)
    CR_MSG_WM_NCPAINT(OnNCPaint)
    CR_MSG_WM_NOTIFY(OnNotify)
    CR_MSG_WM_PAINT(OnPaint)
    CR_MSG_WM_SETFOCUS(OnSetFocus)
    CR_MSG_WM_SETICON(OnSetIcon)
    CR_MSG_WM_SETTEXT(OnSetText)
    CR_MSG_WM_SETTINGCHANGE(OnSettingChange)
    CR_MSG_WM_SIZE(OnSize)
    CR_MSG_WM_SYSCOMMAND(OnSysCommand)
    CR_MSG_WM_THEMECHANGED(OnThemeChanged)
    CR_MSG_WM_WINDOWPOSCHANGED(OnWindowPosChanged)
    CR_MSG_WM_WINDOWPOSCHANGING(OnWindowPosChanging)
    CR_END_MSG_MAP()

    // Message Handlers.
    // This list is in _ALPHABETICAL_ order!
    // TODO(beng): Once this object becomes the WindowImpl, these methods can
    //             be made private.
    void OnActivateApp(BOOL active, DWORD thread_id);
    // TODO(beng): return BOOL is temporary until this object becomes a
    //             WindowImpl.
    BOOL OnAppCommand(HWND window, short command, WORD device, int keystate);
    void OnCancelMode();
    void OnCaptureChanged(HWND window);
    void OnClose();
    void OnCommand(UINT notification_code, int command, HWND window);
    LRESULT OnCreate(CREATESTRUCT* create_struct);
    void OnDestroy();
    void OnDisplayChange(UINT bits_per_pixel, const gfx::Size& screen_size);
    LRESULT OnDwmCompositionChanged(UINT msg, WPARAM w_param, LPARAM l_param);
    void OnEnterMenuLoop(BOOL from_track_popup_menu);
    void OnEnterSizeMove();
    LRESULT OnEraseBkgnd(HDC dc);
    void OnExitMenuLoop(BOOL is_shortcut_menu);
    void OnExitSizeMove();
    void OnGetMinMaxInfo(MINMAXINFO* minmax_info);
    LRESULT OnGetObject(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnImeMessages(UINT message, WPARAM w_param, LPARAM l_param);
    void OnInitMenu(HMENU menu);
    void OnInputLangChange(DWORD character_set, HKL input_language_id);
    LRESULT OnKeyEvent(UINT message, WPARAM w_param, LPARAM l_param);
    void OnKillFocus(HWND focused_window);
    LRESULT OnMouseActivate(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnMouseRange(UINT message, WPARAM w_param, LPARAM l_param);
    void OnMove(const gfx::Point& point);
    void OnMoving(UINT param, const RECT* new_bounds);
    LRESULT OnNCActivate(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnNCCalcSize(BOOL mode, LPARAM l_param);
    LRESULT OnNCHitTest(const gfx::Point& point);
    void OnNCPaint(HRGN rgn);
    LRESULT OnNCUAHDrawCaption(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnNCUAHDrawFrame(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnNotify(int w_param, NMHDR* l_param);
    void OnPaint(HDC dc);
    LRESULT OnReflectedMessage(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnScrollMessage(UINT message, WPARAM w_param, LPARAM l_param);
    LRESULT OnSetCursor(UINT message, WPARAM w_param, LPARAM l_param);
    void OnSetFocus(HWND last_focused_window);
    LRESULT OnSetIcon(UINT size_type, HICON new_icon);
    LRESULT OnSetText(const wchar_t* text);
    void OnSettingChange(UINT flags, const wchar_t* section);
    void OnSize(UINT param, const gfx::Size& size);
    void OnSysCommand(UINT notification_code, const gfx::Point& point);
    void OnThemeChanged();
    LRESULT OnTouchEvent(UINT message, WPARAM w_param, LPARAM l_param);
    void OnWindowPosChanging(WINDOWPOS* window_pos);
    void OnWindowPosChanged(WINDOWPOS* window_pos);

    // Receives Windows Session Change notifications.
    void OnSessionChange(WPARAM status_code);

    typedef std::vector<ui::TouchEvent> TouchEvents;
    // Helper to handle the list of touch events passed in. We need this because
    // touch events on windows don't fire if we enter a modal loop in the context
    // of a touch event.
    void HandleTouchEvents(const TouchEvents& touch_events);

    // Resets the flag which indicates that we are in the context of a touch down
    // event.
    void ResetTouchDownContext();

    // Helper to handle mouse events.
    // The |message|, |w_param|, |l_param| parameters identify the Windows mouse
    // message and its parameters respectively.
    // The |track_mouse| parameter indicates if we should track the mouse.
    LRESULT HandleMouseEventInternal(UINT message,
        WPARAM w_param,
        LPARAM l_param,
        bool track_mouse);

    // Returns true if the mouse message passed in is an OS synthesized mouse
    // message.
    // |message| identifies the mouse message.
    // |message_time| is the time when the message occurred.
    // |l_param| indicates the location of the mouse message.
    bool IsSynthesizedMouseMessage(unsigned int message,
        int message_time,
        LPARAM l_param);

    // Provides functionality to transition a frame to DWM.
    void PerformDwmTransition();

    // Generates a touch event and adds it to the |touch_events| parameter.
    // |point| is the point where the touch was initiated.
    // |id| is the event id associated with the touch event.
    // |event_time| is the current time used for latency calculation.
    // |time_stamp| is the time delta associated with the message.
    void GenerateTouchEvent(ui::EventType event_type,
        const gfx::Point& point,
        unsigned int id,
        base::TimeTicks event_time,
        base::TimeDelta time_stamp,
        TouchEvents* touch_events);

    // Handles WM_NCLBUTTONDOWN and WM_NCMOUSEMOVE messages on the caption.
    // Returns true if the message was handled.
    bool HandleMouseInputForCaption(unsigned int message,
        WPARAM w_param,
        LPARAM l_param);

    HWNDMessageHandlerDelegate* delegate_;

    scoped_ptr<FullscreenHandler> fullscreen_handler_;

    // Set to true in Close() and false is CloseNow().
    bool waiting_for_close_now_;

    bool remove_standard_frame_;

    bool use_system_default_icon_;

    // Whether all ancestors have been enabled. This is only used if is_modal_ is
    // true.
    bool restored_enabled_;

    // The current cursor.
    HCURSOR current_cursor_;

    // The last cursor that was active before the current one was selected. Saved
    // so that we can restore it.
    HCURSOR previous_cursor_;

    // The icon created from the bitmap image of the window icon.
    base::win::ScopedHICON window_icon_;

    // The icon created from the bitmap image of the app icon.
    base::win::ScopedHICON app_icon_;

    // Event handling ------------------------------------------------------------

    // The flags currently being used with TrackMouseEvent to track mouse
    // messages. 0 if there is no active tracking. The value of this member is
    // used when tracking is canceled.
    DWORD active_mouse_tracking_flags_;

    // Set to true when the user presses the right mouse button on the caption
    // area. We need this so we can correctly show the context menu on mouse-up.
    bool is_right_mouse_pressed_on_caption_;

    // The set of touch devices currently down.
    TouchIDs touch_ids_;

    // ScopedRedrawLock ----------------------------------------------------------

    // Represents the number of ScopedRedrawLocks active against this widget.
    // If this is greater than zero, the widget should be locked against updates.
    int lock_updates_count_;

    // Window resizing -----------------------------------------------------------

    // When true, this flag makes us discard incoming SetWindowPos() requests that
    // only change our position/size.  (We still allow changes to Z-order,
    // activation, etc.)
    bool ignore_window_pos_changes_;

    // The last-seen monitor containing us, and its rect and work area.  These are
    // used to catch updates to the rect and work area and react accordingly.
    HMONITOR last_monitor_;
    gfx::Rect last_monitor_rect_, last_work_area_;

    // True the first time nccalc is called on a sizable widget
    bool is_first_nccalc_;

    // Copy of custom window region specified via SetRegion(), if any.
    base::win::ScopedRegion custom_window_region_;

    // If > 0 indicates a menu is running (we're showing a native menu).
    int menu_depth_;

    // Generates touch-ids for touch-events.
    ui::SequentialIDGenerator id_generator_;

    // Indicates if the window needs the WS_VSCROLL and WS_HSCROLL styles.
    bool needs_scroll_styles_;

    // Set to true if we are in the context of a sizing operation.
    bool in_size_loop_;

    // Stores a pointer to the WindowEventTarget interface implemented by this
    // class. Allows callers to retrieve the interface pointer.
    scoped_ptr<ui::ViewProp> prop_window_target_;

    // Number of active touch down contexts. This is incremented on touch down
    // events and decremented later using a delayed task.
    // We need this to ignore WM_MOUSEACTIVATE messages generated in response to
    // touch input. This is fine because activation still works correctly via
    // native SetFocus calls invoked in the views code.
    int touch_down_contexts_;

    // Time the last touch message was received. Used to flag mouse messages
    // synthesized by Windows for touch which are not flagged by the OS as
    // synthesized mouse messages. For more information please refer to
    // the IsMouseEventFromTouch function.
    static long last_touch_message_time_;

    // Time the last WM_MOUSEHWHEEL message is received. Please refer to the
    // HandleMouseEventInternal function as to why this is needed.
    long last_mouse_hwheel_time_;

    // On Windows Vista and beyond, if we are transitioning from custom frame
    // to Aero(glass) we delay setting the DWM related properties in full
    // screen mode as DWM is not supported in full screen windows. We perform
    // the DWM related operations when the window comes out of fullscreen mode.
    // This member variable is set to true if the window is transitioning to
    // glass. Defaults to false.
    bool dwm_transition_desired_;

    // True if HandleWindowSizeChanging has been called in the delegate, but not
    // HandleWindowSizeChanged.
    bool sent_window_size_changing_;

    // Manages observation of Windows Session Change messages.
    scoped_ptr<WindowsSessionChangeObserver> windows_session_change_observer_;

    // This class provides functionality to register the legacy window as a
    // Direct Manipulation consumer. This allows us to support smooth scroll
    // in Chrome on Windows 10.
    scoped_ptr<gfx::win::DirectManipulationHelper> direct_manipulation_helper_;

    // The location where the user clicked on the caption. We cache this when we
    // receive the WM_NCLBUTTONDOWN message. We use this in the subsequent
    // WM_NCMOUSEMOVE message to see if the mouse actually moved.
    // Please refer to the HandleMouseEventInternal function for details on why
    // this is needed.
    gfx::Point caption_left_button_click_pos_;

    // Set to true if the left mouse button has been pressed on the caption.
    // Defaults to false.
    bool left_button_down_on_caption_;

    // The WeakPtrFactories below must occur last in the class definition so they
    // get destroyed last.

    // The factory used to lookup appbar autohide edges.
    base::WeakPtrFactory<HWNDMessageHandler> autohide_factory_;

    // The factory used with BEGIN_SAFE_MSG_MAP_EX.
    base::WeakPtrFactory<HWNDMessageHandler> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(HWNDMessageHandler);
};

} // namespace views

#endif // UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_
